Difficulty has always been encountered when two pieces of material are to be joined accurately together by dowels. The principle difficulty has been in the alignment of the two mating parts that are to be butt joined together and the subsequent drilling of holes in the two mating parts, such that after the holes are drilled and the dowels are inserted in the holes and the two mating parts are joined, the union and surfaces of each mating part will be true and flush with each other. Such accuracy is difficult to achieve with present state of the art dowel drilling jigs wherein said jig is used first on one mating piece and then turned around and used on the opposite mating piece to locate and drill the said opposite mating dowel holes. Herein is one of the main difficulties. That is, when the jig is turned around and used on the mating part any deviation from symmetry of the drill bit guide hole jig or any errors of alignment, or angles of drilling the holes of the first work part, are doubled when drilling a second dowel hole in the second mating work part.
Consequently, in the final assembly of the two parts, any misalignment of the dowel holes of the mating parts due to said assymetricies or operator error, can result in misalignment of the work parts as well as cause bending and stress in the dowels after final assembly of the mating parts. In the hands of a skilled craftsman, the current devices can be used successfully, but only with time-consuming effort and care. Another difficulty of existing dowel jigs is that they cover the work piece and therefore injects guesswork as to where the drill bit will penetrate the work piece.